web-cmd.py: open browser from ioloop callback
web-cmd.py: open browser from ioloop callback

Assuming the callback won't be called until tornado is ready to
receive requests.

Signed-off-by: Rob Browning <1dc5917c2adeeba13d1ef33dbb40691a1b67cc65@defaultvalue.org>

pombredanne/bup,mhoeher/bup,ToxicFrog/bup,jbaber/bup,tjanez/bup,tjanez/bup,mhoeher/bup,pombredanne/bup,ToxicFrog/bup,gevaerts/bup,gevaerts/bup,tjanez/bup,jbaber/bup,pombredanne/bup,gevaerts/bup,ToxicFrog/bup,pombredanne/bup,mhoeher/bup,tjanez/bup,tjanez/bup,pombredanne/bup,gevaerts/bup,jbaber/bup,jbaber/bup,ToxicFrog/bup,ToxicFrog/bup,jbaber/bup,mhoeher/bup,gevaerts/bup,jbaber/bup,mhoeher/bup,tjanez/bup,mhoeher/bup,pombredanne/bup